Most everyone they talked to spoke Russian or Ukrainian, forcing investigators to abandon the usual rules. And when the crucial call came in to 911, it took police several minutes to find a Ukrainian translator and learn from the caller that Nikolay Soltys was hiding in the backyard of his mother's house in the Sacramento suburb of Citrus Heights.

It's a phenomenon that is happening nationwide as law enforcement agencies cope with new immigrant communities.

About 11 percent of the nation -- 30 million people -- is now foreign-born, up from less than 5 percent in 1970, according to the 2000 census.

Minority enclaves are increasingly appearing outside the traditional entry points of California, Florida and New York. The Center for Immigration Studies found states with fast-growing populations like Colorado, North Carolina and Nevada each experienced jumps in foreign-born residents of more than 180 percent since 1990.

''The U.S. may be the most diverse country in the world. It means the community no longer has the shared understanding of what acceptable and unacceptable behavior is,'' said Northwestern University law professor Paul H. Robinson, who helped develop criminal codes for Ukraine and Belarus.

Columbus, Ohio, police carry language identifier booklets to figure out which translator can help with the 30 to 40 language groups in central Ohio.

''It's certainly intensified over the last 10 years,'' said Columbus Sgt. Earl Smith.

It's not just language that challenges police. Deep-seated cultural differences also have an effect.

For instance, Hmong women who have been raped rarely come forward because of the extreme stigma imported from their homeland in the mountains of Southeast Asia.

''They're really abandoned by their families. They're seen as damaged goods,'' said Michael Jordan, a spokesman for St. Paul, Minn., police.

Police there also have run into cultural differences on what constitutes domestic violence.

'''You're charging me with hitting my wife? She's mine. I paid for her,''' Jordan said, paraphrasing one argument. ''In that culture they often pay a dowry, so they feel they own her.''

Detroit police have had a tough time persuading members of the Bangladeshi community to testify against a countryman suspected of harassing fellow immigrants.

''They want to take care of it their way,'' and can't understand American concepts such as due process, said Lt. Paul Janness.

That's not the case in Sacramento, where investigators say distrust of authority and other cultural differences hampered an investigation conducted largely within the region's growing community of 75,000 Russians and Ukrainians.

Police had so little cooperation that Senior Pastor Adam Bondaruk of Bethany Slavic Missionary Church had to plead at the victims' funerals for his countrymen to put aside the fear of police they brought with them from the former Soviet Union. Soltys was eventually captured Thursday.